Cord-shaped knitting-covered bodies and method of making same



Feb. 13, 1934. MElWALD 1,947,302

CORD SHAPED KNITTING COVERED BODIES AND METHOD OF MAKING SAME FiledSept. 3, 1931 Patented Feb. 13, 1934 UNITED STATES CORD-SHAPEDKNITTING-COVERED BODIES AND METHOD OF MAKING SAME Franz Meiwald, Vienna,Austria Application September 3, 1931, Serial No. 561,066, and inGermany August 11, 1931 Russuw 2 Claims. (01. 66--190) I have filedapplications as follows: Germany, August 11, 1931; Czechoslovakia,August 18, 1931; Hungary, August 13, 1931; the Netherlands, August 14,1931.

I This invention relates to strand elements with a knitted tubularcovering, and more particularly to knitting-covered electric conductorsand cables and similar elongated elements. It has already been proposedto provide such bodies, and in particular electric conductors andcables, with a knitted instead of a braided or plaited covering for theprotection of the insulation or as insulation, since in this way aconsiderable saving of material and labour can be eiiected, inconsequence of the very much greater working capacity of the knittingmachine as compared with the rapid braiding machine. The saving thuseffected is the greater the longer is the knitting machine used, andthere is thus an incentive to 90 increase as far as possible the lengthof the loops of the knitted covering. This tendency is, however,accompanied by a certain disadvantage in the appearance of theknitting-covered body, since the rows of knots spaced the length of theloops apart become very prominent, and that more particularly when, forparticular reasons. the longitudinal lines of the stitching runspirally, for which reason the rows of knots become too prominent tomake a smooth appearing surface.

30 Coverings of this type are disclosed for instance in my United StatesLetters Patents numbered 1,814,324 and 1,936,519 which show centralstrand elements enclosed by a knitted covering which, however, has theabove mentioned objections.

The present invention has for' its object to obviate this drawbackwithout increased consumption of thread material and working time, andconsists essentially in effecting the longitudinal displacement, i. e.staggering.', of the neigh- 40 bouring stitches or loops in relation toeach other. The result obtained is particularly effective when thisdisplacement is achieved by spacing of the loops in a row and displacingalternate rows longitudinally of the cable or cord being covered, so

that the loops of each successive row overlie the fioat between adjacentloops of the preceding row.

Such methods of knitting are known per se but have not been employedhitherto in knitting a covering on to cord shaped bodies, in which theyconstitute a new use, by which novel effects and results are producedwhich are of great advantage in circum-knitted strand elements referredto hereinbefore.

In the accompanying drawing, like characters of reference indicate likeparts in the several views, and

Figure 1 is a diagrammatic view of one form 01. knit covering inaccordance with this invention. 1

Figure 2 is a schematic view'oi a part of a knitting machine as used toknit the form shown in Figure 1.

Figure 3 is a view similar to Figure 1 but showing a modified form ofknitting.

Figure 4 is a view similarto Figure 2 but showing the arrangement forknitting the modified form. q

The invention is illustrated in the accompanying drawing by diagrammaticrepresentations of the stitching method, and by diagrammaticrepresentations of two examples of the cam cylinder of the knittingmachine in accordance with the invention, showing the needle guiding. Inthe knitting method shown in Fig. 1 the wales of circumferentialconsecutive loops are somewhat displaced longitudinally in relation toeach other by a circumferential alternative succession of shorter andlonger loops, so that the wales described circumferentially a zigzagline, and are thereby rendered less prominent in the finished covering.For the manufacturing of this type oi knitted covering the cam cylinder1 shown developed in a plane in Fig. 2, with needles 2, 3 of differentlength, are employed. The shape of the cam cylinder implies that eachneedle works twice at each revolution. Long and short needles arearranged alternately in a row, thus effecting the displacement of theloops in relation to each other.

As illustrated in Figure 2, two needles are shown in the needlecylinder, both. of which are operated to move upwardly and downwardly bya single cam curve. In other words, the lower ends of the needles bothengage in the same cam groove. The form of the curve is diagrammaticallyillustrated in Figure 2.

In the knitting method illustrated in Fig. 3, adjacent loops of acircumferential row are double spaced, but not staggered in the row asin Fig. 1. The loops of the next consecutive row which is knitted with adiiferent thread are, however, circumferentially displaced with respectto the position of the loops in the preceding row, so that they overliethe float between adjacent loops of the preceding row, thus againproducing the eifect sought by the invention. In this manner, the loopsof a next consecutive row also cover, and bind against the core, thecircumferentiall'y extending thread. nes le: .vnich eonalso be employedfor obtaining the displacement nect adjacent loops of preceding row.ihis of the stitches in accordance with. the present is extremelyimportant in covering a core by a knitted fabric, because as far as I amaware this is the first successful attempt to cover a core, for instancea cable or wire, with knitted fabric which can not be unraveled. Thereason for this is that by the manner in which this fabric is knitted,namely, with a plurality of independent threads, several independentknitted fabrics are knitted into and between another, so that threads ofone i'a'oric bind the threads 0; the other fabric. The cam cylinder 4(Fig. i) employed for the manufacture of this type oi covering has twogrooves 5, 6, each of which has two high points. The individual highpoints are displaced 90 to each other. Counting the needlesconsecutively and beginning with one or those guided by the upper grooveall odd numbered n edles are guided by this upper groove while all evennumbered needles are guided by the lower groove. The knitting is doneover a suitable core or body 7 around which the stitch line or i s runspirally. The alternate heads or upper ends 9 and 10 of the knittingloops are ar ranged on a staggered line 11 which extends spirally aroundthe core *2.

The described forms of construction can be combine iurther Emittingmethods can invention.

I claim:

1. The combination with a central strand element of a "Knitted fabricsurrounding said element and being composed of a plurality of threadsformed into a plurality of individual spiral rows of circinnferentiallyspaced loops with floats b ween the adjacent loops, the loops of eachsuccessive row extending part into the spaces between the adjacent loopsof the next adjacent row and overlying the floats between said adjacentloops whereby the loops of ad. jacent rows form a circumferential zigzagiine around the element.

2. The method of covering strand elements consistine' in knitting aroundsaid strand elea of individual spiral rows of loops 115,. L relativelyl'ng floats between the adjacent loops, and :ning the loops of eachsuccessive row part way into the spaces between the adjment loops oi?the next adjacent row in position to overlie the floats between theadjacent loops whereby the loops of the adjacent rows form acircumferential zigzag line around the element.

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